docs: def is_geophysical(ds, variable):
      '''
      Returns true if the dataset's variable is likely a geophysical variable
  
      :param netCDF4.Dataset ds: An open netCDF dataset
      :param str variable: Name of the variable
      '''
      ncvar = ds.variables[variable]
  
      if getattr(ncvar, 'cf_role', None):
          return False
  
      # Check for axis
      if getattr(ncvar, 'axis', None):
          return False
  
      standard_name_test = getattr(ncvar, 'standard_name', '')
      unitless = is_unitless(ds, variable)
  
      if not isinstance(standard_name_test, basestring):
          warnings.warn("Variable {} has non string standard name, "
                        "Attempting cast to string".format(variable))
          try:
              standard_name = str(standard_name_test)
          except ValueError:
              warnings.warn("Unable to cast standard name to string, excluding "
                            "from geophysical variables")
      else:
          standard_name = standard_name_test
  
      # Is the standard name associated with coordinates
      if standard_name in {'time', 'latitude', 'longitude',
                           'height', 'depth', 'altitude'}:
          return False
  
      if variable in get_coordinate_variables(ds):
          return False
  
      if variable in get_auxiliary_coordinate_variables(ds):
          return False
  
      # Is it dimensionless and unitless?
      if len(ncvar.shape) == 0 and unitless:
          return False
  
      # Is it a QC Flag?
      if 'status_flag' in standard_name or hasattr(ncvar, 'flag_meanings'):
          return False
  
      # Is it a §7.1 Cell Boundaries variable
      if variable in get_cell_boundary_variables(ds):
          return False
  
      if variable == get_climatology_variable(ds):
          return False
  
      # Is it a string but with no defined units?
      if ncvar.dtype.char == 'S':
          return False
  
      # Is it an instrument descriptor?
      if variable in get_instrument_variables(ds):
          return False
  
      # What about a platform descriptor?
      if variable in get_platform_variables(ds):
          return False
  
      # Skip count variables too
      if hasattr(ncvar, 'sample_dimension'):
          return False
  
      return True